Elttid-pre sstrre-brake device



T. H. THOMAS.

FLu-Ip PRESSURE BRAKE nEvlcE. APPLICATION FILED DEC.2I, 1920.

Patented Oct. 17, 1922.

INVENToR THOMAS H. THOMAS ATTORNEY Patented Qct. 17, 1922.

'PATENT onirica.

Tiioiviss n. Tirer/ias, or nnenwoon, reNNsYLvANia, assieiioav ro 'riin WnsriNe- House .ein BRAKE COMPANY, or Wiiiiinanine, raNNsvLviiNie, e coaroiaii'rioir r y oF PENNSYLVANIA.

FLUID-PRESSURE-BRAKE DEVCE.

Application filed December 25., 1920. Serial No. 432,236.

'To Z iii/'wm it may concern "Re it known that I, TiioMAs H. THOMAS,

sfr citizen of the United States, residing at Brake Devices, of which the following is a specification. f i

This invention relates to fluid pressure brakes, and more particularly to means for effecting the graduali release of the brakes and the recharge oi the auxiliary reservoir.

The principal object of my invention is to provide means for graduating the release of thebrakes in which the auxiliary reservoir is recharged at a rate corresponding with the rate at which fluid is released from the brake cylinder.

In the accompanying drawing, the single ligure is a diagrammatic view, mainly in section, of a Huid pressure brake equipment embodying my invention.

As shown in the drawing, the brake equipment may comprise a triple valve device 1 having a piston chamber 2connected to thebrake pipe 3 and containing piston 4, and

a valve chamber 5, connected to the auxiliary reservoir 6,'andrv containing a main slide valve 7 and a graduating slide valve 8 adapted to be operated by piston 4 Jfor v"controlling the admission and release .of

f by passage 15 to the auxiliary reservoir 6.A

fluid under cylinder 9. y

According to my invention, a valve depressure to and from a brake vice 10 for graduating the release of the Vbrakesr is provided and comprises a cas-` ing containing ai diaphragm 11 having a chamber 12 at one side connected by pipe and passage 113 with the brake Ipipe 3 and a chamber" 14 at the opposite side connected The movement of diaphragm 11 operates a valve 16 for controlling communication from a supplemental reservoir 17 through passage 18 to chamber 14 and passage 15.

' The exhaust passage 19 of the triple valve device 1` isv connected by pipe 20 and passage' 21 toa chamber 22" in the valve device `1'0'and communication from chamber 22 to'an` atmospheric exhaust passage 23 is controlled by a valve 24.

The operation of valve 24 is controlled bv the action of a. set of three diaphragme 25,

26, and 27, having differential areas, the

area of diaphragm 26 being greater than the area of diaphragme 27 and the area of the diaphragm 25 being preferably intermediate the areas of the diaphragme 26 and 27.

rThe chamber 28 at one side of the dia phragm 25 is constantly subject to the fluid pressurein the supplemental reservoir 17, as supplied through passages 18 and 29, the chamber 80 intermediate the diaphragms `26 and .27 is subject to the fluid pressure in the auxiliary reservoir 6, the diaphragm 27 is subject on one side to the pressure in the triple valve exhaust chamber 22, and the chamber o1 intermediate the diaphragms 25 and 26 is open to the atmosphere by way of a passage '32.

The valve 24- is movably mounted in the valve stem 33 and is acted upon by a spring A34, thus permitting the valve to find its seat, in spite oit any inaccuracies in machining or in assemblingthefparts.

In operation, the auxiliary reservoir is normally charged with fluid under pressure supplied from the brake pipe 3 through the usual `feed groove 85, and the supplemental reservoir 17 may be charged from the brake' pipe by way of pipe 36 containing a nonreturn check valve 87.

The brake pipe pressure in lchamber l2 and the auxiliary reservoir pressure in .chamber 14 being normally equal, the valve 16 will be held seated by spring 39.

if the brakes have been applied in the usual manner by effecting a reduction in brake pipe pressure, so that Huid under pressure is supplied from the auxiliary reservoir 6 to the brake cylinder 9, the release of the brakes may thereafter be graduated by increasing the brake pipe pressure a predetermined amount.

The triple valve piston is then shifted to release position, inwhich the brake cylinder 9 is connected by cavity 38 in slide valve 7 with passage 19 and the chamber 22.

The increase in brake pipe pressure in chamber 12 operates the diaphragm 11 to open the valve 16 and permit the liow of Huid from the supplemental reservoir 17 to passage 15 and the auxiliary reservoir 6, the flow continuing until the auxiliary reservoir pressure has been increased to substantially equal the increased brake pipe pressure, when the valve 16 will be moved to its seat by spring 39.

The increase in auxiliary reservoir pressure acts on the differential area of the dia phragm 26, and With the brake cylinder pressure acting in chamber 22 overcomes the pressure of the supplemental reservoir acting in chamber Q8 on diaphragm 25.

The mlre 2e* is then liifted from its seat, permitting fluid to be released from chamber 22 and the bralre cylinder 9.

lVlien the brake cylinder pressure has been reduced a predetermined amount, the diaphragms move so as to permit the valve 2li; to seat. rThe ratio of the reduction in brake cylinder pressure to the increase in auxiliary reservoir pressure being determined by the relative areas of the diaphragme 26 and 27.

The brake cylinder pressure may be further reduced by increasing the brake pipe pressure a further amount, so as to again operate the diaphragm 11 and open the valve 16. The further increase in auxiliary reservoir pressure then operates on the diaphragm 25 to open the valve 2i and permit a further release ot fluid from the brake cylinder.

1t will nouv be seen that fluid yis released from the bralre cylinder according as the auxiliary reservoir pressure is increased so that the auxiliary reservoir is recharged in proportion to the rate at which the fluid in the bra'lre cylinder is released in graduating the release of the brakes.

By employing` the diaphragm 25 subject to the pressure normally carried in the system as supplied to the reservoir li", it will be seen that the device will operate at any desiredl standard of pressure carried in the bralre pipe Without the necessity for adjusting any of the parts.

Having now described my invention, what' 'i l claim neiv and desire to secure by Letters Patent, is:

l. 1n a fluid pressure brake, the carabina- 'tion with a brake pipe, auxiliary reservoir, and brake cylinder, or means operated upon anincrease vin auxiliary reservoir pressure in releasing the brakes for releasing fluid from the brake cylinder.

ln a fluid pressure brake, the combination with a brake pipe, auxiliary reservoir, and brake cylinder, of means operated upon an increz in brake pipe pressure for supplying 'fluid to the auxiliary reservoir and means operated according` to the increase in auxiliary reservoir pressure Vfor releasing lfluid from ythe brake cylinder.

In a fluid pressure brake` the combination with a bralze pipe, auxiliary reservoir, and brake cylinder. of means operated upon apredeteiuiined increase in bralre pipe pressure, in effecting the release of lthe brakes,

set

for supplying fluid to the auxiliary reservoir and means operated according to the increase in auxiliary reservoir pressure Jfor releasing fluid from the brake cylinder.

4. ln a fluid pressure brake, the combination with a brake pipe, auxiliary reservoir,

nd brake cylinder, of tivo diaphragms of different areas subject to auxiliary reservior pressure, one of said diaphragms being subject on its opposite side to brake cylinder pressure., a valve operated by said diaphragms `t'or controlling the release of fluid from the brake cylinder, and means operated upon an increase in brake pipe pressure roi? supplying fluid to the auxiliary reservoir.

5. ln a fluid pressure brake, the lcombination with brake pipe, auxiliary reservoir, brake cylinder, and a 'supplemental reservoir adapted to be charged from the brake pipe, ol? two diaphragme of different areas subject to auxiliary reservoir pressure, one of said diaphragms being subject on its opposite side to bralre cylinder pressure, a third diaphragm subject to the pressure in supplemental reservoir opposing the brake cylinder pressure, and a valve operued by said diaphragms for controlling'the release of fluid from the brake cylinder.

6. ln a fluid pressure brake, the combination With a brake pipe, auxiliary reservoir, brake cylinder, and a supplemental reservoir f, vptedlto be charged from the brake pipeI of tivo diaphragms of different areas subject to auxiliary'reservoir pressure, one of said diaphragms being subject on its op posite side to brake cylinder pressure, a

third (iliaphragm subject to the pressure in4 the supplemental reservoir opposing the bralre cylinder pressure, a valve operated by said diaphragme for controlling the release of fluid fromthe brake cylinder, and inea s operated upon an increase in brake essure for supplying fluid to the aux- "eservoir,

ln a fluid pressure brake, the combination with a brake pipe, auxiliary reservoir, brake cylinder, and a supplemental reservoir adapted to be charged from the brake pipe, of tufo diaphragms of different areas subject `to auxiliary'reservoir pressure, one of said diaphragms being subject on its opi, sideto brake cylinder pressure, a g. vdiaphragm subject tothe pressure in the supplemental reservoir opposing the l*brake cylinder pressure, a valve operated for supplying fluid' from the supplemental reeryoir te the auxiliary reservoir.

In testimony whereof l. have hereunto `hand A@["HO'MAS H. THOMAS, 

